/Engine/Source/Runtime/SlateCore/Public/Rendering/DrawElements.h
Create a new CachedElementList, occurs when adding a cached element whose top level draw widget is not already part of some cache
[FSlateCachedElementsHandle](API\Runtime\SlateCore\Rendering\FSlateCachedElementsHandle) AddCache ( const [SWidget](API\Runtime\SlateCore\Widgets\SWidget) * Widget )